Multi-jaw chuck

ABSTRACT

A chuck having a plurality of jaw carrying rods slidably arranged within bores inclined relative to the chuck axis. The rods may be axially shifted in opposite directions to thereby increase and decrease the diameter of the circle defined by the jaws for gripping and releasing the peripheral surface of a workpiece. The rods are insertable and removable from the front of the chuck and after insertion are operatively connected to an actuator slide within the chuck by rotary indexing of the rods within their respective bores.

United States Patent Morawski et al.

[54] MULTI-JAW CHUCK [72] Inventors: London T. Mora'wski, Mt. Clemens;John J. Parker, Warren, both of Mich.

[731 Assignee: The John J. Parker Living Trust, by

said Parker [22] Filed: Dec. 24, 1970 211 App]. No.: 101,210

[52] U.S. Cl. .....279/1l0,-2 79/60, 279/123 [51] Int. Cl. ..B23h 31/10[58] Field of Search ..279/60, 110, H9, 123

[56] References Cited UNITED STATES PATENTS 3,248,122 4/1966 Roddy..279/l l0 [4511 Dec. 26, 1972 Primary Examiner-Francis S. Husar YAttorney-Barnes,Kisselle, Raisch & Choate [s71 ABSTRACT A chuck having aplurality of jaw carrying rods slidably arranged within bores inclinedrelative to the chuck axis. The rods may be axially shifted in oppositedirections to thereby increase and decrease the diameter of the circledefined by the jaws for gripping and releasing the peripheral surface ofa'workpiece. The rods are insertable and removable from the frontof thechuck and after insertion are operatively con- I nected to an actuatorslide within the chuck by rotary indexing of the rods within theirrespective bores 6 Claims, 5 Drawing Figures PATENTEDBEBZB m 3,707,292

INVENTORS LONDON T. MORAWSKI JOHN J PARKER 75 in; ATTORNEYS PATENTEDnmzs\912 SHEET 2 BF 2 INVENTORS LONDON T. MORAWSKI JOHN J. PARKER ATTORNEYSMULTI-JAW CHUCK This invention relates to chucks and particularly tomulti-jaw chucks of the drawbar type especially adapted for holdingcastings and forgings.

When a chuck of this type is used with a machine tool such as a lathe itis often necessary to replace the entire chuck when a different sizedworkpiece is being machined since the chuck jaws are not readilyreplaceable. g

It is therefore the principal object of this invention to provide amulti-jaw chuck in which the jaws may be readily replaced from the frontof the chuck.

Another important object of this invention is the provision of amulti-jaw chuck of simple yet rigid construction having replaceablechuck jaws which are operatively connected to' ajaw actuator by means ofa key and notch arrangement.

Other features and objects of the invention will become apparent fromthe'accompanying description and drawings in which: I

FIG. 1 is a front view of a multi-jaw chuck of the present inventionmounted on a machine tool spindle.

FIG. 2 is a sectional-view. taken along line 2-2 in FIG. 1. a a

FIG. 3 is a view similar to a portion of FIG. 2 and showing additionalfeatures therein.

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3.

FIG. 5 is a perspective view of the actuator slide of the presentinvention.

Referring to FIGS. 1 and 2 there is shown a chuck of the presentinvention mounted on a spindle or spindle adaptor 12 of a machine'tool14 by means of circumferentially spaced attaching bolts 16. Chuck 10comprises a body 18 having a front face 20 and a rear face 22. A forwardextension 24 projects forwardly of front face 20 while a rear extension26 projects rearwardly from face 22 so as to seat body 18 concentricallywith the spindle axis 28.

A plurality of three circular bores 30 are arranged in body 18. Whenviewed from the front of the chuck, bores 30 are circumferentiallyequally spaced about axis 28. Bores 30 extend rearwardly from face 20through body 18 and are similarly inclined radially outwardly in therearward direction. Body 18 is also provided with a central axial bore32 extending forwardly through rear extension 26 so as to communicatewith the rearward portions of bores 30. A plurality of three .arcuategrooves 34 are formed in forward extension 24 as continuations of bores30.

Slidably arranged within each inclined bore 30 is a jaw rod 36. The rearportion of jaw rod 36 is cylindrical in shape so as to have a closesliding fit within bore 30. As better shown in FIG. 3, the front portionof rod 36 carries serrations 38 for grip'ping'a workpiece 40. Rod 36 isalso provided with a slot 42 which extends lengthwise from rear end 44of the rod for approximately half its length, terminating as at 46.

Referring also to FIG. 4, a notch 48 in rod 36 extends arcuatelyapproximately 90 about the rod axis adjacent termination 46 of slot 42.A short slot 50 in the radially outward surface of rod 36 receives theend of a pin 52 inserted through a hole 53 in body 18.

An actuator slide 54 is arranged within bore 32 for imparting motion tojaw rods 36. As better shown in FIG. 5, slide 54 comprises a cylindricalslide body 56 having a shank 58 extending forwardly from body 56. Aplurality of three flats 60 are machined on shank 58 at similarinclinations relative to axis 28. Centrally located at the forward endof each flat 60 is a key 62 which projects radially outwardly so as toextend into notch 48 on rod 36 when the jaw rods are operativelyinstalled in the chuck. An axially extending key 64 on slide 54 engagesa keyway 66 in body 18 so as to prevent rotation therebetween. Slide 54is actuated by a drawbar 68 on machine tool 14, the forward motion ofthe slidebeing limited by the engagement of key 64 with shoulder 68 on'body 18, and the rearward motion by the engagement of stop '70 with head72 of bolt 74 which is affixed to body 18 as at 76. 3

With chuck 10 mounted on spindle 12 jaw rods 36 are expeditiously Iinserted therein by the following e Rear end 44 of rod 36'is insertedinto the front of bore 30 with slot 42 facing radially inwardly foralignment with key 62. The engagement'of key. 62 with slot 42 allows rod36 to beinserted until notch 48 is adjacent key 62. Rod 36 is thenindexed, that is, rotated about the axis of bore 30, in the clockwisedirection as viewed in FIG. 4. Key 6.2 is now engaged bynotch 48 so asto render rod 36 operatively connected with actuator-slide 54. Pin 52 isthen threaded into hole 53 so that its inner end projects into slot50.The length of slot 50 is sufficientto allow shifting of rod 36 betweenan engaged position and a disengaged position relative to the workpiecewhile the width of slot 50 permits a slight rotation of rod 36 about itsaxis to thereby enable the serrated jaw portion 38 to accommodate slightsurface irregularities in the workpieces.

In order to bring jaw rods 36 to the work engaging position, slide 54 isshifted to the left as viewed in FIG.

2. This causes rods 36 to move axially rearwardly and radially outwardlyso that serrations 38 engage the inner circumference of workpiece 40. Inorder to release the workpiece, slide 54 is returned to the right asviewed'in FIG. 2. t

Whenever it is desired to change jaw rods 36 the are still within thescope of this invention. For example,

to enable the chuck to grip workpieces around the outer surface thereofrather than around an inner surface, inclined bores 30 could be inclinedradially inwardly in the rearward direction with slide 54 being shiftedto the right as viewed in FIG. 2 to shift the rods to the work engagingposition. In another variation, keys could be formed on jaw rods 36which are indexed to engage notches in slide 54. In this case, keywayscould be formed in bores 30 for receiving the jaw rod keys as jaw rods36 are inserted through the front of the chuck. A notch would beprovided adjacent each keyway so that when jaw rod 36 is indexedrelative to bore 30, the key is brought into locking engagement with thenotch in slide 54.

We claim: 1

1. A chuck adapted to be mounted on a rotary spindle of a machine toolfor retaining a workpiece thereon comprising a body having an axiscoaxial with the spindle axis, a plurality of bores in said bodysimilarly inclined relative to the body axis and extending rearwardlyfrom the front of the chuck, axially shiftable actuating means adaptedto be operatively connected to means on said machine tool forreciprocating said actuating means, a jaw rod slideably arranged withineach sociated with each jaw rod, each of said jaw rods being adapted tobe rotated so as to radially align the slot therein with its respectivekey on the actuating means to enable insertion of each jaw rod into itsinclined bore and thereafter 'rotatably indexed to engage the notch withsaid key so as to interengage said actuating means with each jaw rod sothat when the actuating means is axially shifted in said central borethe jaw rods are shifted in their inclined bores.

2. The combination called for in claim 1 and including additional meansfor releasably locking said key and'notch in interengaged position.

3. The combination called for in claim 1 including a second axiallyextending slot in said jaw rod and a pin projecting from said body intosaid last-mentioned slot for limiting the rotation of said jaw rodwithin said inclined bore while permitting axial movement thereof.

4. The combination called for in claim 1 wherein said notch is locatedadjacent the forward end of the slot in each jaw rod. I

5. A chuck adapted to be mounted on a rotary spindle of a machine toolfor retaining a workpiece thereon I comprising a body having anaxis'coaxial with thespindle axis, a plurality of bores in said bodysimilarly inclined relative to the body axis and extending rearwardlyfrom the front of .the chuck, axially shiftable actuating meansad'apted'to be operatively connected to means on said machine tool forreciprocating said actuating means, a jaw rod slideably arranged withineach of said inclined bores, said jaw rods being insertable into saidinclined bores from the front of said chuck,

- said actuating means having a plurality of radially outtuating meansfor length wardly extending keys thereon associated one with each ofsaid jaw rods, means on each of said jaw rods forming a recess on theouter periphery thereof to provide a-- clearance space with saidinclined bore which extends lengthwise of the bore and has a radialextent at-least equal to the extent to which the key on the actuatingmeans projects radially into said inclined bores whereby to permit saidjaw rods-to be inserted into said inclined bores when the jaw rods areoriented to radially align said clearance spaces with said keys andmeans on said jaw rods enabling the jaw rods to be rotated afterinsertion in said inclined bores to relatively shift said keys out ofradial registration with said clearance spaces to interlock the jaw rodsand the acwise movement together so that when said actuating means isaxially shifted the jaw rods are shifted axially within said inclinedbores.

6. The combination called for in claim 5 wherein said last-mentionedmeans comprises means forming a circumferentially extending recess onthe outer periphery of each jaw rod communicating with said lengthwiseextending recess and sized to receive said keys upon rotation of the jawrod in its respective inclined bore.

1. A chuck adapted to be mounted on a rotary spindle of a machine toolfor retaining a workpiece thereon comprising a body having an axiscoaxial with the spindle axis, a plurality of bores in said bodysimilarly inclined relative to the body axis and extending rearwardlyfrom the front of the chuck, axially shiftable actuating means adaptedto be operatively connected to means on said machine tool forreciprocating said actuating means, a jaw rod slideably arrangeD withineach of said inclined bores, said jaw rods being insertable into saidinclined bores from the front of said chuck, said body including acentral axial bore extending forwardly from the rear of said body withthe rearward ends of the inclined bores communicating with said centralbore, said actuating means being axially shiftable in said central bore,each of said jaw rods having a slot extending lengthwise from the rearend thereof and a notch therein spaced axially from the rear end of therod and circumferentially adjacent said slot, a radially outwardlyextending key on said actuating means associated with each jaw rod, eachof said jaw rods being adapted to be rotated so as to radially align theslot therein with its respective key on the actuating means to enableinsertion of each jaw rod into its inclined bore and thereafterrotatably indexed to engage the notch with said key so as to interengagesaid actuating means with each jaw rod so that when the actuating meansis axially shifted in said central bore the jaw rods are shifted intheir inclined bores.
 2. The combination called for in claim 1 andincluding additional means for releasably locking said key and notch ininterengaged position.
 3. The combination called for in claim 1including a second axially extending slot in said jaw rod and a pinprojecting from said body into said last-mentioned slot for limiting therotation of said jaw rod within said inclined bore while permittingaxial movement thereof.
 4. The combination called for in claim 1 whereinsaid notch is located adjacent the forward end of the slot in each jawrod.
 5. A chuck adapted to be mounted on a rotary spindle of a machinetool for retaining a workpiece thereon comprising a body having an axiscoaxial with the spindle axis, a plurality of bores in said bodysimilarly inclined relative to the body axis and extending rearwardlyfrom the front of the chuck, axially shiftable actuating means adaptedto be operatively connected to means on said machine tool forreciprocating said actuating means, a jaw rod slideably arranged withineach of said inclined bores, said jaw rods being insertable into saidinclined bores from the front of said chuck, said actuating means havinga plurality of radially outwardly extending keys thereon associated onewith each of said jaw rods, means on each of said jaw rods forming arecess on the outer periphery thereof to provide a clearance space withsaid inclined bore which extends lengthwise of the bore and has a radialextent at least equal to the extent to which the key on the actuatingmeans projects radially into said inclined bores whereby to permit saidjaw rods to be inserted into said inclined bores when the jaw rods areoriented to radially align said clearance spaces with said keys andmeans on said jaw rods enabling the jaw rods to be rotated afterinsertion in said inclined bores to relatively shift said keys out ofradial registration with said clearance spaces to interlock the jaw rodsand the actuating means for lengthwise movement together so that whensaid actuating means is axially shifted the jaw rods are shifted axiallywithin said inclined bores.
 6. The combination called for in claim 5wherein said last-mentioned means comprises means forming acircumferentially extending recess on the outer periphery of each jawrod communicating with said lengthwise extending recess and sized toreceive said keys upon rotation of the jaw rod in its respectiveinclined bore.